| Network Working Group | M. Douglass |
| Internet-Draft | Spherical Cow Group |
| Updates: 5545,5546 (if approved) | May 15, 2018 |
| Intended status: Standards Track | |
| Expires: November 16, 2018 |
Event Publishing Extensions to iCalendar
draft-ietf-calext-eventpub-extensions-07
This specification updates [RFC5545] and [RFC5546] by introducing a number of new iCalendar properties and components which are of particular use for event publishers and in social networking.
This specification also defines a new STRUCTURED-DATA property for iCalendar [RFC5545] to allow for data that is directly pertinent to an event or task to be included with the calendar data.
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."
This Internet-Draft will expire on November 16, 2018.
Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
The currently existing iCalendar standard [RFC5545] lacks useful methods for referencing additional, external information relating to calendar components. Additionally there is no standard way to provide rich text descriptions or meta-data associated with the event.
Current practice is to embed this information as links in the description or to add non-standard properties as defined in [RFC5545] section 3.8.8.2.
This document updates [RFC5545] to define a number of properties and a component referencing such external information that can provide additional information about an iCalendar component. The intent is to allow interchange of such information between applications or systems (e.g., between clients, between client and server, and between servers). Formats such as VCARD are likely to be most useful to the receivers of such events as they may be used in other applications - such as address books.
This specification defines a new PARTICIPANT component. Many people or groups may participate in an event. This component provides detailed information. Such participants may act as attendees to the event (or derived events) or may just provide a reference - perhaps for mailing lists.
The following properties are defined in this specification
In addition the SOURCE property defined in [RFC7986] is redefined to allow VALUE=TEXT and broaden its usage.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
Previous extensions to the calendaring standards have been largely restricted to the addition of properties or parameters. This is partly because iCalendar libraries had trouble handling components nested deeper than those defined in [RFC5545]
In a break with this 'tradition' this specification introduces one of these extensions as a component rather than a property. This is a better match for the way XML and JSON handles such structures and allows richer definitions.
It also allows for the addition of extra properties inside the component and resolves some of the problems of trying to add detailed information as a parameter.
The properties defined here can all reference external meta-data which may be used by applications to provide enhanced value to users. By providing type information as parameters, clients and servers are able to discover interesting references and make use of them, perhaps for indexing or the presenting of additional related information for the user.
The [RFC5545] LOCATION property provides only an unstructured single text value for specifying the location where an event (or task) will occur. This is inadequate for use cases where structured location information (e.g. address, region, country, postal code) is required or preferred, and limits widespread adoption of iCalendar in those settings.
Using STRUCTURED-LOCATION, information about a number of interesting locations can be communicated, for example, address, region, country, postal code as well as other informations such as the parking, restaurants and the venue. Servers and clients can retrieve the objects when storing the event and use them to index by geographic location.
When a calendar client receives a calendar component it can search the set of supplied properties looking for those of particular interest. The TYPE and FMTTYPE parameters, if supplied, can be used to help the selection.
The PARTICIPANT component is designed to handle common use cases in event publication. It is generally important to provide information about the organizers of such events. Sponsors wish to be referenced in a prominent manner. In social calendaring it is often important to identify the active participants in the event, for example a school sports team, and the inactive participants, for example the parents.
The PARTICIPANT component can also be used to provide useful extra data about an attendee. For example a LOCATION property inside the PARTICIPANT gives the actual location of a remote attendee.
The main motivation for these properties has been event publication but there are opportunities for use elsewhere. The following use cases will describe some possible scenarios.
In putting together a concert there are many participants: piano tuner, performer, stage hands etc. In addition there are sponsors and various contacts to be provided. There will also be a number of related locations. A number of events can be created, all of which relate to the performance in different ways.
There may be an iTip [RFC5546] meeting request for the piano tuner who will arrive before the performance. Other members of staff may also receive meeting requests.
An event can also be created for publication which will have a PARTICIPANT component for the pianist providing a reference to vcard information about the performer. This event would also hold information about parking, local subway stations and the venue itself. In addition, there will be sponsorship information for sponsors of the event and perhaps paid sponsorship properties essentially advertising local establishments.
These additions also provide opportunities for the travel industry. When booking a flight the PARTICIPANT component can be used to provide references to businesses at the airports and to car hire businesses at the destination.
The embedded location information can guide the traveller at the airport or to their final destination. The contact information can provide detailed information about the booking agent, the airlines, car hire companies and the hotel.
For a meeting, the size of a room and the equipment needed depends to some extent on the number of attendees actually in the room.
A meeting may have 10 attendees non of which are co-located. The current ATTENDEE property dos not allow for the additon of such meta-data. The PARTICIPANT property allows attendees to specify their location.
eventc = "BEGIN" ":" "VEVENT" CRLF
eventprop *alarmc *participantc
"END" ":" "VEVENT" CRLF
eventprop =/ *(
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
styleddescription / strucloc / strucres / sdataprop
;
)
todoc = "BEGIN" ":" "VTODO" CRLF
todoprop *alarmc *participantc
"END" ":" "VTODO" CRLF
todoprop =/ *(
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
styleddescription / strucloc / strucres / sdataprop
;
)
journalc = "BEGIN" ":" "VJOURNAL" CRLF
jourprop *participantc
"END" ":" "VJOURNAL" CRLF
jourprop =/ *(
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
styleddescription / sdataprop
;
)
The following changes to the syntax defined in iCalendar are made here. New elements are defined in subsequent sections.
This specification makes use of the LABEL parameter which is defined in [RFC7986]
This parameter is defined by the following notation:
loctypeparam = "LOCTYPE" "=" param-value
This parameter is defined by the following notation:
restypeparam = "RESTYPE" "=" restypevalue CRLF
restypevalue = ("ROOM"
/ "PROJECTOR"
/ "REMOTE-CONFERENCE-AUDIO"
/ "REMOTE-CONFERENCE-VIDEO"
/ x-name ; Experimental status
/ iana-token) ; Other IANA-registered
; values
This parameter is defined by the following notation:
orderparam = "ORDER" "=" integer ;Must be greater than or equal to 1
This parameter is defined by the following notation:
schemaparam = "SCHEMA" "=" DQUOTE uri DQUOTE
STRUCTURED-DATA;FMTTYPE=application/ld+json; SCHEMA="https://schema.org/FlightReservation"; ENCODING=BASE64;VALUE=BINARY:Zm9vYmFy
The SOURCE property defined in [RFC7986] is redefined to allow VALUE=TEXT and broaden its usage to any component.
This property is defined by the following notation:
source = "SOURCE" sourceparam
(
(
";" "VALUE" "=" "URI"
":" uri
) /
(
";" "VALUE" "=" "TEXT"
":" text
)
)
CRLF
sourceparam = *(
;
; the following are OPTIONAL
; but MUST NOT occur more than once
;
(";" fmttypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
;
)
The following is an example referring to a VCARD.
SOURCE;FMTTYPE=text/vcard;VALUE=URL:
http://dir.example.com/vcard/contacts/contact1.vcf
This parameter is defined by the following notation:
participanttype = "PARTICIPANT-TYPE" "=" partvalue CRLF
partvalue = ("ACTIVE"
/ "INACTIVE"
/ "SPONSOR"
/ "CONTACT"
/ "BOOKING-CONTACT"
/ "EMERGENCY-CONTACT"
/ "PUBLICITY-CONTACT"
/ "PLANNER-CONTACT"
/ "PERFORMER"
/ "SPEAKER"
/ x-name ; Experimental status
/ iana-token) ; Other IANA-registered
; values
The following is an example of this property:
PARTICIPANT-TYPE:SPEAKER
The registered values for the PARTICIPANT-TYPE property have the meanings described here:
This parameter is defined by the following notation:
calendaraddress = "CALENDAR-ADDRESS" "=" cal-address
This property is defined by the following notation:
styleddescription = "STYLED-DESCRIPTION" styleddescparam ":"
(
(
";" "VALUE" "=" "URI"
":" uri
) /
(
";" "VALUE" "=" "TEXT"
":" text
)
)
CRLF
styleddescparam = *(
;
; The following are OPTIONAL,
; but MUST NOT occur more than once.
;
(";" altrepparam) / (";" languageparam) /
(";" fmttypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
)
The following is an example of this property. It points to an html description.
STYLED-DESCRIPTION;VALUE=URI:http://example.org/desc001.html
This property is defined by the following notation:
strucloc = "STRUCTURED-LOCATION" struclocparam
(
(
";" "VALUE" "=" "URI"
":" uri
) /
(
";" "VALUE" "=" "TEXT"
":" text
)
)
CRLF
struclocparam = *(
;
; the following are OPTIONAL
; but MUST NOT occur more than once
;
(";" fmttypeparam) /
(";" labelparam) /
(";" languageparam) /
(";" loctypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
)
The following is an example of this property. It points to a venue.
STRUCTURED-LOCATION;LABEL="The venue":
http://dir.example.com/venues/big-hall.vcf
This property is defined by the following notation:
strucres = "STRUCTURED-RESOURCE" strucresparam /
(
(
";" "VALUE" "=" "URI"
":" uri
) /
(
";" "VALUE" "=" "TEXT"
":" text
)
)
CRLF
strucresparam = *(
;
; the following are OPTIONAL
; but MUST NOT occur more than once
;
(";" fmttypeparam) /
(";" labelparam) /
(";" languageparam) /
(";" restypeparam) /
;
; the following is OPTIONAL
; and MAY occur more than once
;
(";" other-param)
)
The following is an example of this property. It refers to a projector.
STRUCTURED-RESOURCE;value=uri;restype="projector":
http://dir.example.com/projectors/3d.vcf
This property is defined by the following notation:
sdataprop = "STRUCTURED-DATA" sdataparam
(":" text) /
(
";" "ENCODING" "=" "BASE64"
";" "VALUE" "=" "BINARY"
":" binary
) /
(
";" "VALUE" "=" "URI"
":" uri
)
CRLF
sdataparam = *(
;
; The following is OPTIONAL for a URI value,
; RECOMMENDED for a TEXT or BINARY value,
; and MUST NOT occur more than once.
;
(";" fmttypeparam) /
(";" schemaparam) /
;
; The following is OPTIONAL,
; and MAY occur more than once.
;
(";" other-param)
;
)
STRUCTURED-DATA;FMTTYPE=application/ld+json;
SCHEMA="https://schema.org/SportsEvent";
VALUE=TEXT:{\n
"@context": "http://schema.org"\,\n
"@type": "SportsEvent"\,\n
"homeTeam": "Pittsburgh Pirates"\,\n
"awayTeam": "San Francisco Giants"\n
}\n
This property is defined by the following notation:
participantc = "BEGIN" ":" "PARTICIPANT" CRLF
partprop *alarmc
"END" ":" "PARTICIPANT" CRLF
partprop = *(
;
; The following are REQUIRED,
; but MUST NOT occur more than once.
;
dtstamp / participanttype /
;
; The following are OPTIONAL,
; but MUST NOT occur more than once.
;
created / description / last-mod / priority / seq /
source / status / scheduleaddress / summary / url /
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
attach / categories / comment /
contact / rstatus / related /
resources / x-prop / iana-prop
;
)
The following is an example of this component. It contains a SOURCE property which points to a VCARD providing information about the event participant.
BEGIN:PARTICIPANT
PARTICIPANT-TYPE:PRINCIPAL_PERFORMER
SOURCE:http://dir.example.com/vcard/aviolinist.vcf
END:PARTICIPANT
The following is an example for the primary contact.
BEGIN: PARTICIPANT
SOURCE;FMTTYPE=text/vcard;
http://dir.example.com/vcard/contacts/contact1.vcf
PARTICIPANT-TYPE:PRIMARY-CONTACT
DESCRIPTION:A contact:
END:PARTICIPANT
A PARTICIPANT component may represent someone or something that needs to be scheduled as defined for ATTENDEE in [RFC5545] and [RFC5546]. The PARTICIPANT component may also represent someone or something that is NOT to receive scheduling messages.
A PARTICIPANT component is defined to be schedulable if
If both of these conditions apply then the participant defined by the value of the URL property will take part in scheduling operations as defined in [RFC5546].
An appropriate use for the PARTICIPANT component in scheduling would be to store SEQUENCE and DTSTAMP properties associated with replies from each ATTENDEE. A LOCATION property within the PARTICIPANT component might allow better selection of meeting times when participants are in different timezones.
The following are some examples of the use of the properties defined in this specification. They include additional properties defined in [RFC7986] which includes IMAGE.
The following is an example of a VEVENT describing a concert. It includes location information for the venue itself as well as references to parking and restaurants.
BEGIN:VEVENT
CREATED:20170216T145739Z
DESCRIPTION: Piano Sonata No 3\n
Piano Sonata No 30
DTSTAMP:20171116T145739Z
DTSTART;TZID=America/New_York:20170315T150000Z
DTEND;TZID=America/New_York:20170315T163000Z
LAST-MODIFIED:20170216T145739Z
SUMMARY:Beethoven Piano Sonatas
UID:123456
STRUCTURED-LOCATION;LABEL="The venue":
http://dir.example.com/venues/big-hall.vcf
STRUCTURED-LOCATION;LABEL="The venue":
http://dir.example.com/venues/parking.vcf
IMAGE;VALUE=URI;DISPLAY=BADGE;FMTTYPE=image/png:h
ttp://example.com/images/concert.png
BEGIN:PARTICIPANT
PARTICIPANT-TYPE:SPONSOR
SOURCE:http://example.com/sponsor.vcf
END:PARTICIPANT
BEGIN:PARTICIPANT
PARTICIPANT-TYPE:PERFORMER:
SOURCE:http://www.example.com/people/johndoe.vcf
END:PARTICIPANT
END:VEVENT
The following is an example of a VEVENT describing a meeting. One of the attendees is a remote participant.
BEGIN:VEVENT
CREATED:20170216T145739Z
DTSTAMP:20101116T145739Z
DTSTART;TZID=America/New_York:20170315T150000Z
DTEND;TZID=America/New_York:20170315T163000Z
LAST-MODIFIED:20170216T145739Z
SUMMARY:Conference plaaning
UID:123456
ORGANIZER:mailto:a@example.com
ATTENDEE;PARTSTAT=ACCEPTED;CN=A:mailto:a@example.com
ATTENDEE;RSVP=TRUE;CN=B:mailto:b@example.com
BEGIN:PARTICIPANT
PARTICIPANT-TYPE:ACTIVE:
SOURCE:http://www.example.com/people/b.vcf
LOCATION:At home
END:PARTICIPANT
END:VEVENT
Applications using these properties need to be aware of the risks entailed in using the URIs provided as values. See [RFC3986] for a discussion of the security considerations relating to URIs.
Security considerations relating to the "ATTACH" property, as described in [RFC5545], are applicable to the "STRUCTURED-DATA" property.
Properties with a "URI" value type can expose their users to privacy leaks as any network access of the URI data can be tracked. Clients SHOULD NOT automatically download data referenced by the URI without explicit instruction from users. This specification does not introduce any additional privacy concerns beyond those described in [RFC5545].
This section defines updates to the tables defined in [RFC5545] and new tables.
This document defines the following new iCalendar properties to be added to the registry defined in Section 8.2.3 of [RFC5545]:
| Property | Status | Reference |
|---|---|---|
| CALENDAR-ADDRESS | Current | RFCXXXX, Section 7.2 |
| PARTICIPANT-TYPE | Current | RFCXXXX, Section 7.1 |
| SOURCE | Current | RFCXXXX, Section 6 |
| STRUCTURED-DATA | Current | RFCXXXX, Section 7.6 |
| STYLED-DESCRIPTION | Current | RFCXXXX, Section 7.3 |
| STRUCTURED-LOCATION | Current | RFCXXXX, Section 7.4 |
| STRUCTURED-RESOURCE | Current | RFCXXXX, Section 7.5 |
This document defines the following new iCalendar property parameters to be added to the registry defined in Section 8.2.4 of [RFC5545]:
| Property Parameter | Status | Reference |
|---|---|---|
| LOCTYPE | Current | RFCXXXX, Section 5.1 |
| ORDER | Current | RFCXXXX, Section 5.3 |
| RESTYPE | Current | RFCXXXX, Section 5.2 |
| SCHEMA | Current | RFCXXXX, Section 5.4 |
This document defines the following new iCalendar components to be added to the registry defined in Section 8.3.1 of [RFC5545]:
| Component | Status | Reference |
|---|---|---|
| PARTICIPANT | Current | RFCXXXX, Section 8.1 |
This section defines new registration tables for PARTICIPANT-TYPE and RESTYPE values. These tables maybe updated using the same approaches laid down in Section 8.2.1 of [RFC5545]
The following table has been used to initialize the participant types registry.
| Participant Type | Status | Reference |
|---|---|---|
| ACTIVE | Current | RFCXXXX, Section 7.1 |
| INACTIVE | Current | RFCXXXX, Section 7.1 |
| SPONSOR | Current | RFCXXXX, Section 7.1 |
| CONTACT | Current | RFCXXXX, Section 7.1 |
| BOOKING-CONTACT | Current | RFCXXXX, Section 7.1 |
| EMERGENCY-CONTACT | Current | RFCXXXX, Section 7.1 |
| PUBLICITY-CONTACT | Current | RFCXXXX, Section 7.1 |
| PLANNER-CONTACT | Current | RFCXXXX, Section 7.1 |
| PERFORMER | Current | RFCXXXX, Section 7.1 |
| SPEAKER | Current | RFCXXXX, Section 7.1 |
The following table has been used to initialize the resource types registry.
| Resource Type | Status | Reference |
|---|---|---|
| PROJECTOR | Current | RFCXXXX, Section 5.2 |
| ROOM | Current | RFCXXXX, Section 5.2 |
| REMOTE-CONFERENCE-AUDIO | Current | RFCXXXX, Section 5.2 |
| REMOTE-CONFERENCE-VIDEO | Current | RFCXXXX, Section 5.2 |
The author would like to thank Chuck Norris of eventful.com for his work which led to the development of this RFC.
The author would also like to thank the members of CalConnect, The Calendaring and Scheduling Consortium, the Event Publication technical committee and the following individuals for contributing their ideas and support:
Cyrus Daboo, John Haug, Dan Mendell, Ken Murchison, Scott Otis,
None at the moment
calext-v04 2017-10-11 MD
calext-v03 2017-10-09 MD
calext-v02 2017-04-20 MD
calext-v01 2017-02-18 MD
calext-v00 2016-08-?? MD
v06 2016-06-26 MD
v05 2016-06-14 MD
v04 2014-02-01 MD
v03 2013-03-06 MD
v02 2012-11-02 MD
v01 2012-10-18 MD Many changes.
2011-01-07
v00 2007-10-19 MD Initial version